Design Of Discrete Sliding Mode Control Research Articles

Robust discrete sliding mode controller design for a single-phase onboard integrated electric vehicle charger with disturbance estimation

A new sliding mode controller (SMC) design is proposed for a single-phase current source rectifier (CSR) integrated into onboard electric vehicle (EV) chargers. The controller's design aims to reduce the impact of varying grid impedance on the CSR's performance by using a disturbance estimator. The proposed method utilizes the Lagrange extrapolation technique for disturbance estimation, which accurately estimates disturbances caused by changes in the grid impedance. The precise state-space equation provided by the disturbance estimator is essential for designing the SMC, which can effectively handle mismatched disturbances. To mitigate the impact of the capacitor inductance filter's resonance frequency, a virtual parallel resistance with the capacitor is used, reducing the resonance amplitude. The proposed controller also controls the power factor to ensure the capacitor voltage and grid current are in phase. Simulation and experimental results demonstrate that the proposed method achieves stability and meets the harmonic content limitations of the IEC61000–3–2 standard. The total harmonic distortion (THD) is also kept below 5% despite changes in the grid impedance, demonstrating the effectiveness of the proposed method in handling varying grid conditions.

Discrete Sliding Mode Control Design for Bilateral Teleoperation System via Adaptive Extended State Observer.

The goal of this paper is to improve the synchronization control performance of nonlinear teleoperation systems with system uncertainties in the presence of time delays. In view of the nonlinear discrete states of the teleoperation system in packet-switched communication networks, a new discrete sliding mode control (DSMC) strategy is performed via a new reaching law in task space. The new reaching law is designed to reduce the chattering and improve control performance. Moreover, an adaptive extended state observer (AESO) is used to estimate the total system disturbances. The additional gain of AESO is adjusted in time to decrease the estimation errors of both system states and disturbances automatically and improve the estimation performances of the AESO. Finally, the validity of the designed control strategy is demonstrated by both simulation and experiments. Furthermore, the experimental comparison results indicate that the improvement is achievable with the proposed AESO and DSMC.

Model‐free output feedback discrete sliding mode control with disturbance compensation for precision motion systems

This study proposes a novel model-free output feedback discrete sliding mode control (OFDSMC) with disturbance compensation to achieve high performance for precision motion systems encountering model uncertainties and disturbances. Traditional discrete sliding mode control design requires model and/or state information. In this study, OFDSMC with disturbance compensation is first developed by using a parametric input–output model such that no system states are needed. The essential four control terms of OFDSMC with disturbance compensation is revealed. Then a data-driven control method is introduced into OFDSMC to eliminate the need for the parametric model. The proposed model-free OFDSMC facilitates a rapid implementation without either a parameter model or a state observer, and achieves good robustness against model uncertainties and disturbances. Finally, three simulation cases are presented to illustrate the effectiveness and enhanced performance of the proposed approach.

Discrete sliding mode control for hybrid synchronization of continuous Lorenz systems with matched/unmatched disturbances

This paper is concerned with the hybrid synchronization of master-slave Lorenz systems with uncertainties. A new systematic design procedure to synchronize continuous master-slave Lorenz chaotic systems is proposed by using a discrete sliding mode control (DSMC). In contrast to the previous works, the design of DSMC can be simplified and only a single controller is needed to realize chaos synchronization. The proposed DSMC ensures the occurrence of the sliding mode. When the controlled system is in the sliding manifold, the effect of disturbances including matched and unmatched cases are discussed. The proposed results conclude the synchronization error of controlled master-slave systems with matched disturbances can be fully derived to zero or robustly suppressed in an estimated bound even with unmatched disturbances, which is not addressed in the literature. The numerical simulation results demonstrate the success and effectiveness of the proposed DSMC developed in this paper.

Hybrid chaos control of continuous unified chaotic systems using discrete rippling sliding mode control

In this paper, a new systematic design procedure to stabilize continuous unified chaotic systems based on discrete sliding mode control (DSMC) is presented. In contrast to the previous works, the concept of rippling control is newly introduced such that the design of DSMC can be simplified and only a single controller is needed to realize chaos suppression. As expected, under the proposed DSMC law, the unified system can be stabilized in a manner of ripple effect, even when the external uncertainty is present. Last, two examples are included to illustrate the effectiveness of the proposed rippling DSMC developed in this paper.

Discrete sliding mode controller design based on the LQR suboptimal approach with application on ac servo motor

A systematic and simple discrete sliding mode controller design scheme based on the suboptimal approach is presented. The behaviors of the control system can be determined through a preferred performance index. The AC servomotor position control is obtained using only the q‐axis voltage control loop. The proposed method is simulated and experimented with to verify the capability of this new sliding mode control algorithm. Properties such as easy implementation, fast response, and robustness with relation to external loads are demonstrated.